# Authenticating with a User and Password For this example, start the server using: ```bash > nats-server --user myname --pass password ``` You can encrypt passwords to pass to `nats-server` using a simple [tool](../../nats-tools/natscli.md): ```bash > nats server passwd ? Enter password [? for help] ********************** ? Reenter password [? for help] ********************** $2a$11$qbtrnb0mSG2eV55xoyPqHOZx/lLBlryHRhU3LK2oOPFRwGF/5rtGK ``` and use the hashed password in the server config. The client still uses the plain text version. The code uses localhost:4222 so that you can start the server on your machine to try them out. ## Connecting with a User/Password When logging in with a password `nats-server` will take either a plain text password or an encrypted password. {% tabs %} {% tab title="Go" %} ```go // Set a user and plain text password nc, err := nats.Connect("127.0.0.1", nats.UserInfo("myname", "password")) if err != nil { log.Fatal(err) } defer nc.Close() // Do something with the connection ``` {% endtab %} {% tab title="Java" %} ```java Options options = new Options.Builder(). server("nats://localhost:4222"). userInfo("myname","password"). // Set a user and plain text password build(); Connection nc = Nats.connect(options); // Do something with the connection nc.close(); ``` {% endtab %} {% tab title="JavaScript" %} ```javascript let nc = NATS.connect({url: server.nats, user: "myname", pass: "password"}); ``` {% endtab %} {% tab title="Python" %} ```python nc = NATS() await nc.connect(servers=["nats://myname:password@demo.nats.io:4222"]) # Do something with the connection. ``` {% endtab %} {% tab title="Ruby" %} ```ruby require 'nats/client' NATS.start(servers:["nats://myname:password@127.0.0.1:4222"], name: "my-connection") do |nc| nc.on_error do |e| puts "Error: #{e}" end nc.on_reconnect do puts "Got reconnected to #{nc.connected_server}" end nc.on_disconnect do |reason| puts "Got disconnected! #{reason}" end nc.close end ``` {% endtab %} {% tab title="TypeScript" %} ```typescript let nc = await connect({url: server.nats, user: "myname", pass: "password"}); ``` {% endtab %} {% tab title="C" %} ```c natsConnection *conn = NULL; natsOptions *opts = NULL; natsStatus s = NATS_OK; s = natsOptions_Create(&opts); if (s == NATS_OK) s = natsOptions_SetUserInfo(opts, "myname", "password"); if (s == NATS_OK) s = natsConnection_Connect(&conn, opts); (...) // Destroy objects that were created natsConnection_Destroy(conn); natsOptions_Destroy(opts); ``` {% endtab %} {% endtabs %} ## Connecting with a User/Password in the URL Most clients make it easy to pass the user name and password by accepting them in the URL for the server. This standard format is: > nats://_user_:_password_@server:port Using this format, you can connect to a server using authentication as easily as you connected with a URL: {% tabs %} {% tab title="Go" %} ```go // Set a user and plain text password nc, err := nats.Connect("myname:password@127.0.0.1") if err != nil { log.Fatal(err) } defer nc.Close() // Do something with the connection ``` {% endtab %} {% tab title="Java" %} ```java Connection nc = Nats.connect("nats://myname:password@localhost:4222"); // Do something with the connection nc.close(); ``` {% endtab %} {% tab title="JavaScript" %} ```javascript let url = `nats://myname:password@127.0.0.1:${port}`; let nc = NATS.connect(url); ``` {% endtab %} {% tab title="Python" %} ```python nc = NATS() await nc.connect(servers=["nats://myname:password@demo.nats.io:4222"]) # Do something with the connection. ``` {% endtab %} {% tab title="Ruby" %} ```ruby require 'nats/client' NATS.start(servers:["nats://myname:password@127.0.0.1:4222"], name: "my-connection") do |nc| nc.on_error do |e| puts "Error: #{e}" end nc.on_reconnect do puts "Got reconnected to #{nc.connected_server}" end nc.on_disconnect do |reason| puts "Got disconnected! #{reason}" end nc.close end ``` {% endtab %} {% tab title="TypeScript" %} ```typescript let url = `nats://myname:password@127.0.0.1:${port}`; let nc = await connect({url: url}); ``` {% endtab %} {% tab title="C" %} ```c natsConnection *conn = NULL; natsOptions *opts = NULL; natsStatus s = NATS_OK; s = natsOptions_Create(&opts); if (s == NATS_OK) s = natsOptions_SetURL(opts, "nats://myname:password@127.0.0.1:4222"); if (s == NATS_OK) s = natsConnection_Connect(&conn, opts); (...) // Destroy objects that were created natsConnection_Destroy(conn); natsOptions_Destroy(opts); ``` {% endtab %} {% endtabs %}